Ok I'm Confused!

[Miller2009]

I got a aqua one aqua style 850 on the website It says it 165 litre but when I've put my dimensions into a aquarium calculator it's saying its 214 litre which one do I believe? The size is 84x44x58cm (33x17x23 inches ish!)

 

[the_lock_man]

I'm sure I recall reading this a few months back, and I think it's an error on A1's website.

 

[DrRob]

The calculators can't cope with curved fronted tanks either. They have no way of knowing the amount of curve, and the sellers will always give the biggest dimensions.
 
Personally, I'm a fan of using meters on the hosepipe or containers to measure how much water actually went in, makes calculations far easier in the future.

 

[Miller2009]

So is the 165litre the true size?

 

[dgwebster]

you will need to do a little maths to figure it out properly.
 
You will have the volume of your basic tank: shortest depth x width x height
 
You then need to work out the bow area volume. Personally, I would do it the following way:
 
work it out the same as the rest of the tank: (deepest depth - shortest depth) x width x height
 
Work out the bow to no bow area ratio. E.g. if (deepest depth - shortest depth) was 10CM and the width was 100cm, this gives you 1000cm2
 
this is where it starts getting harder as your bow front will not be half a circle, but an area of a segment (part of a trivial pursuit "wedge").
 
Look up this http/www.regentsprep.org/regents/math/geometry/GP14/CircleSectors.htm in "Area of a Segment in a Circle" for the mathmatics and some lovely diagrams.
 
Now you have the area, get your percentage to the rectangular part of your bow tank, e.g. if the area of the bow segment is 600cm2 you have 60% of the area as part of your tank. apply this 60% to your bow end volume (e.g. if it was not bowed, it would be 100litres, but it is bowed so you have 60 litres.
 
add this to the main rectangular section of your tank.

 

[attibones]

http/www.fishtanksandponds.co.uk/calculators/bowfrontvolcalc.html

You could also just use a bow front calculator like the one above.

 

[dgwebster]

Sssshhhhh, stopping people from learning maths here!

 

[Shelster]

Ha ha love it attibones!

Dgwebster, are you a teacher?
......or do you just love doing maths? :s

 

[Sophie]

Sssshhhhh, stopping people from learning maths here!

 
My brain melted as soon as you said the word math.

 

[Baccus]

When I first get a new tank I usually will measure it and find out its true potential for volume, but only after I have added substrate do I fill the tank with water to a set mark on the glass. I then measure from the top of the substrate to the mark and use this to calculate the true volume of water in my tank.
If the tanks small then multiple trips with a measuring jug and filling the tank to a set height also works.

 

[dgwebster]

Ha ha love it attibones!
Dgwebster, are you a teacher? ......or do you just love doing maths? :s

Hehe no, but I do love maths For reference though, I'm an analyst

My brain melted as soon as you said the word math.

I do this a lot at work to colleagues too. Actually, last week I had to make a change to a formula I once wrote, as I sat reading it I got one of the worst headaches I have had in a while. I would post the formula here to send your sanity off with your brain but it is now protected intellectual property of my employer (now where is my trumpet...)

 

[Sophie]

 

My brain melted as soon as you said the word math.

I do this a lot at work to colleagues too. Actually, last week I had to make a change to a formula I once wrote, as I sat reading it I got one of the worst headaches I have had in a while. I would post the formula here to send your sanity off with your brain but it is now protected intellectual property of my employer (now where is my trumpet...)
 

 
It's ok, I read the first like two sentences of your 'working out' above and my brain automatically shut down to protect itself from the harmful intellectual rays

 

[TwoTankAmin]

And then there another issue. Most tanks, at least in the states, are measured on the outside of the glass. An example is a used 150 gal. I purchased
 
Outside dimensions 72in x 18in x 27.75in = about 155 gal.
Inside dimensions    71in x 17in x 26.65in = about 139 gal.   (height assumes filling to within .5 in of top edge)
 
Tank is sold as a 150, but is it?

 

[DrRob]

We have the same with tank dimensions here. I suspect that the ignoring of the dimension change internally comes from a combination of lazy maths and the fact that in the older days tanks were frequently not all that tall and were mostly made from 6mm float glass, so the modern rimless tanks with 10-12mm thick walls weren't considered. It's amazing what that extra 6mm on each dimension does to the volume.